The Experimental Irradiation core provides for the use of radiation by the members of the University of Michigan Comprehensive Cancer Center (UMCCC). The services of this core are critical to a variety of users in the UMCCC such as those Interested in radiation biology and radiation therapy, and those for whom radiation serves a research tool. Thus, it serves the goal of the Cancer Center to encourage basic research as well as translation and clinical applications. The irradiation core maintains and operates the irradiators and also consults with each investigator before initiation of a project, The experience and expertise of the director and manager allow them to offer Investigators Information on dosage and treatment regimens, particularly In animal studies, so that experimental resources are used In an optimal way. Another goal of the core is to foster Interactions between the users of the core by connecting investigators who have used radiation In various types of experiments over the last several years. Use of the Experimental Irradiation core by a variety of members of the Cancer Center is exemplified by the distribution of users. The 53 Cancer Center members who utilize the core participate In 10 Programs Including Breast Oncology, Cancer Cell Biology, Experimental Therapeutics, Gastrointestinal Oncology, and Radiation Sciences, among others. In order to provide this vital service, the core maintains 4 Irradiation devices. The 2 orthovoltage units (In the Medical Science I and Biomedical Science buildings) are used for irradiations of cell cultures and animals (primarily mice and rats but also available for use with rabbits and dogs). The core also maintains a small animal irradiator located In tine specific pathogen free area of the mouse housing in ULAM. The availability of this unit allows Investigators to perform Irradiations without removing immunodeficient mice from the quarantined facility. The fourth Irradiator Is for low dose rate (0.1-0.3 Gy/hour) irradiations. This irradiator, located within the Radiation Oncology department in the Medical Science I Building is built inside a humidified CO{2} Incubator, permitting studies of chronic exposure to very low radiation dose rates. The core is planning to expand Its services to also offer Cancer Center members the opportunity to Irradiate cell or DNA samples with ultraviolet light of different wavelengths.